AUSTRALIAN Wool Innovation has outlined the direction of a new sheep genetics program to be considered by its board later this year that will investigate the accuracy of early-life assessment of the genetic merit of sheep.
The proposed new Lifetime Productivity Project is based on feedback from the industry of moves toward collecting more information on individual animals at younger ages.
And while the project may draw criticism as being a replacement for AWI’s Information Nucleus Flock investment, AWI says the need for improved lifetime productivity data has been around for decades, well before the nucleus flock, and requires data from larger numbers of sheep.
A planning team – including up to nine organisations and research bodies with a history of sheep breeding research – is drafting the project proposal to go to the AWI board for consideration in July or August. There will be a three to four-month industry consultation period before then to receive feedback on the proposal from growers groups, researchers and other stakeholders.
AWI head of on-farm R&D Jane Littlejohn said while breeding values were increasingly accepted by sheep breeders as an effective genetic evaluation tool, there were still issues to resolve to improve their acceptance.
“We must focus on the reasons why more wool producers and stud breeders have not taken up these new technologies faster and whether it can be improved,” she said.
Dr Littlejohn said the proposed project would examine issues around adoption by breeders of Australian Sheep Breeding Values including:
- Are early-life assessments of productivity good indicators of actual lifetime productivity?
- Do plainer sheep hold their productivity at older ages?
- Are higher indexed animals at young ages strongly correlated with a higher net profit per hectare?
- Quantifying the trade-off between high reproductive performance (rearing more lambs in a lifetime) and the possible effect on the productivity of the animal (fleece and bodyweight).
“This project will significantly improve our understanding of the genetics of lifetime reproductive performance and its interaction with other traits such as growth and wool production,” she said.
“The progeny bred in the project would be evaluated over their lifetime for a range of wool, meat, disease and reproduction traits. DNA samples will be collected for genomic evaluation of predictors of lifetime performance.
“Additionally, the availability of lifetime performance information, effects such as birth-rearing type and age-of-dam, pedigree and genomic information will contribute to the development of genomic-enhanced breeding values for lifetime traits.”
AWI program manager sheep health, welfare and productivity Geoff Lindon said the proposed project would involve buying 4000-5000 ewes and locating them at three sites - a high rainfall, low rainfall-pastoral and mixed farming Mediterranean environment.
The ewes would be joined for two years and then sold. Data on the wether lambs would be recorded before they were sold. Ewe lambs would be kept and then joined over five years and data collected on them.
Mr Lindon said the project would be expensive but it was still in the design phase and no costings had been completed. AWI would canvass options for cash and in-kind support from other sources and organisations.
He said the issue of lifetime productivity had been a long-standing industry concern.
“The recent discussion for the lifetime productivity trial started 12 to 18 months ago,” he said.
“Some breeders were interested to looking at classing and assessing sheep at 8-9 months of age with 8-9 months’ wool rather than at 10 months with six months’ wool.”
The planning team is conducting due diligence on previous research flock work – including the nucleus flock – to avoid repetition and identify gaps.
“Lifetime productivity has been around for several decades and well before INF1 and 2 so it’s not a result of any INF1 or 2 decision-making,” he said.
“The INF is designed for genomic R&D and there are a lot fewer numbers of progeny and spread out over a larger number of sites. So the design at this stage of this is different and we have much larger numbers of progeny. We need large numbers of ewes by a sire lambing at 2, 3, 4, 5 and 6-year-old.”
AWI’s Lifetime Productivity Project
The proposed project aims to:
- Estimate genetic parameters (heritability, genetic and phenotypic correlations) for lifetime productivity traits in wool and meat production. It will extend work through the Post-Weaning Fleece Traits Project by evaluating relationships between post-weaning fleece traits, other early age traits and lifetime productivity.
- Evaluate effects of reproduction and fleeceweight on lifetime productivity in a range of Merino genotypes.
- Evaluate selection strategies – from current industry selection practices to genomic-enhanced selection – for their ability to maintain or improve lifetime productivity in Merino sheep.
- Provide data from a pedigreed resource flock that may contribute to the development and validation of genomic-enhanced technologies and breeding values and an understanding of traits that drive lifetime Merino productivity.
- Demonstrate how ram breeding flock management can be simplified by using genomic technology and provide a benefit:cost evaluation of its use.